My family and I went to the IKC show last weekend in Chicago and saw a lot of great looking GWP's.
My question has to do with one of the dogs that was shown. He looked like his back legs were bowed out(looked like he had been on a horse for serveral days). The poor dog couldn't keep up with its handler while going around the ring but otherwise looked good.

I was just wondering what could have been wrong with the dog and why it was shown in such a state if it is abmormal?

Poor rear end conformation is something that you will see in the show ring, not just in GWP. It is not usually(except for hip dysplasia) that something is "wrong" with those dogs like an illness, but it is a matter of being poorly put together. You will see wide, narrow, straight in the stifles, crooked and any combination. Generally, dogs with poor conformation should not be bred and will not hold up in the field as well over time. I have been astounded at some of the dogs trotting around a ring. What will surprise you even more after you watch it over time, is when some of those poor rear end dogs are put up by the judges.